C

//求兩個數的最大公約數
int gcd(int a,int b)
{
int r;
if(a < b)        //a < b，則交換兩個數
{
int temp = a;
a = b;
b = temp;
}


r = a % b;
while(r != 0)
{
a = b;
b = r;
r = a % b;
}
return b;
}
//求兩個數的最小公倍數數
int lcm(int a,int b)
{
return a*b/gcd(a,b);
}